Pump bushing device and associated methods

ABSTRACT

A pump bushing device that is adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing device, including a cylindrical body defining an axial bore extending therethrough for accommodating a shaft of a pump; a plurality of circumferentially spaced-apart, axially-extending, angled slots formed in an inner peripheral wall of the axial bore; and a plurality of apertures corresponding to the plurality of angled slots, the plurality of apertures extending radially inward at an angle from the outer periphery of the cylindrical body to the axial bore. Wherein the plurality of angled slots and the plurality of apertures receive pressurized flushing fluid.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This non-provisional utility patent application claims priority to Applicant's copending provisional patent application, entitled “PUMP BUSHING”, U.S. Serial No. 60/297,971, filed Jun. 13, 2001, which is hereby incorporated in full by reference.

FIELD OF THE INVENTION

[0002] The present invention relates generally to a pump bushing device and associated methods. More specifically, the present invention relates to a rotary pump bushing that is adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing.

BACKGROUND OF THE INVENTION

[0003] In centrifugal or rotary pumps, such as those used in pulp and paper manufacturing, mining operations, and similar working environments, a slurry of abrasive debris may collect in a seal cavity of the pump. Typically, this debris is trapped in the seal cavity by a pump bushing that accommodates an impeller shaft of the pump. The result is increased friction, decreased pump efficiency, and decreased pump life.

[0004] Thus, what is needed is a rotary pump bushing that is adapted and configured to admit pressurized flushing fluid into the seal cavity of the pump, flushing the debris therefrom without removal of the pump bushing. What is also needed is a rotary pump bushing that has a relatively simple design, is relatively easy to manufacture, and is relatively inexpensive to produce.

BRIEF SUMMARY OF THE INVENTION

[0005] In various embodiments of the present invention, a rotary pump bushing is provided that is defined by a cylindrical body having an axial bore extending therethrough for accommodating an impeller shaft of a pump. A plurality of circumferentially spaced-apart, axially-extending, angled slots are formed in an inner peripheral wall of the axial bore. The angled slots receive pressurized flushing fluid through a plurality of corresponding apertures that extend radially inward at an angle from the outer periphery of the cylindrical body to the axial bore. This angular orientation of the slots and the apertures imparts rotation to the pressurized flushing fluid, aiding in the removal of debris from a seal cavity of the pump.

[0006] In one preferred embodiment of the present invention, a pump bushing device that is adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing device, includes a cylindrical body defining an axial bore extending therethrough for accommodating a shaft of a pump; a plurality of circumferentially spaced-apart, axially-extending, angled slots formed in an inner peripheral wall of the axial bore; and a plurality of apertures corresponding to the plurality of angled slots, the plurality of apertures extending radially inward at an angle from the outer periphery of the cylindrical body to the axial bore. Wherein the plurality of angled slots and the plurality of apertures receive pressurized flushing fluid.

[0007] In another preferred embodiment of the present invention, a method for admitting pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of a pump bushing device, includes providing a cylindrical body defining an axial bore extending therethrough for accommodating a shaft of a pump; providing a plurality of circumferentially spaced-apart, axially-extending, angled slots formed in an inner peripheral wall of the axial bore; and providing a plurality of apertures corresponding to the plurality of angled slots, the plurality of apertures extending radially inward at an angle from the outer periphery of the cylindrical body to the axial bore. Wherein the plurality of angled slots and the plurality of apertures receive pressurized flushing fluid.

[0008] These and other aspects of the present invention will become more readily apparent to those of ordinary skill in the art based upon the following detailed description of the invention taken in conjunction with the drawings described herein below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] So that those of ordinary skill in the art to which the present invention pertains will more readily understand how to make and use the pump bushing device of the present invention, preferred embodiments thereof will be described in detail herein below with reference to the drawings, wherein:

[0010]FIG. 1 is a perspective view of one embodiment of a pump bushing adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing;

[0011]FIG. 2 is a side elevation view of the pump bushing of FIG. 1;

[0012]FIG. 3 is a cross-sectional view of the pump bushing of FIG. 2 taken along line 3-3;

[0013]FIG. 4 is a front end view of the pump bushing of FIG. 1;

[0014]FIG. 5 is a cross-sectional view of the pump bushing of FIG. 2 taken along line 5-5;

[0015]FIG. 6 is a perspective view of another embodiment of a pump bushing adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing;

[0016]FIG. 7 is a side elevation view of one half of a cylindrical body of the pump bushing of FIG. 6;

[0017]FIG. 8 is a cross-sectional view of the pump bushing of FIG. 7 taken along line C-C;

[0018]FIG. 9 is a side elevation view of another half of the cylindrical body of the pump bushing of FIG. 6;

[0019]FIG. 10 is a front end view of the pump bushing of FIG. 6; and

[0020]FIG. 11 is a partial cross-sectional view of the pump bushing of FIG. 9 taken along line D-D.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Referring now to the drawings, wherein like reference numerals identify like structural elements and features of the pump bushing of the present invention, there is illustrated in FIG. 1 one embodiment of a pump bushing adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing. The pump bushing is designated generally by reference numeral 10 herein.

[0022] Referring to FIG. 1, in one embodiment of the present invention, the pump bushing 10 includes a cylindrical body 12 including two hemi-cylindrical portions 12 a and 12 b that are secured together by, for example, threaded fasteners or dowel pins (see FIG. 5). This configuration enables the pump bushing 10 to be installed in and/or removed from a pump (not shown), such as a centrifugal pump or a rotary pump, relatively easily. Preferably, the cylindrical body 12 has an axial bore 14 extending therethrough for accommodating an impeller shaft (not shown) of the pump.

[0023] Referring to FIGS. 2 and 3, a plurality of circumferentially spaced-apart, axially-extending, angled slots 16 or troughs are defined in an inner peripheral wall 18 of the axial bore 14. For example, as illustrated in FIG. 4, the centerline of each of the plurality of angled slots 16 varies or tapers approximately 0.219 inches from beginning to end. Those of ordinary skill in the art will readily appreciate that this dimension may be modified without departing from the spirit or scope of the present invention. Preferably, the angled slots 16 are radially tapered, i.e. the angled slots 16 become shallower as they approach the end of the axial bore 14. The angled slots 16 receive pressurized flushing fluid through a plurality of corresponding circumferentially spaced-apart inlet ports 20 or apertures that extend radially inward at an angle from the outer periphery of the cylindrical body 12 to the axial bore 14. The angled slots 16 extend from the inlet ports 20 to a common annular discharge groove 22 formed at the end of the axial bore 14 (see FIG. 1). This angular orientation of the slots 16 and the inlet ports 20 imparts rotation to the pressurized flushing fluid, aiding in the removal of debris from a seal cavity of the pump.

[0024] In an alternative embodiment of the present invention, each of the plurality of angled slots 16 extends directly from an inlet port groove 26 to the axial bore 14. Thus, in this configuration, there are no corresponding circumferentially spaced-apart inlet ports 20 or apertures that extend radially inward at an angle from the outer periphery of the cylindrical body 12 to the axial bore 14. In this alternative embodiment of the present invention, the pressurized flushing fluid is introduced directly into each of the plurality of angled slots 16.

[0025] Referring to FIG. 3, each of the plurality of inlet ports 20 extends radially inward from the inlet port groove 26 in the outer periphery of the cylindrical body 12 to the axial bore 14 at an angle of approximately 25 degrees relative to the longitudinal axis of the pump bushing 10. Those of ordinary skill in the art will readily appreciate that this dimension may be modified without departing from the spirit or scope of the present invention. The orientation of the angled slots 16 and each of the plurality of inlet ports 20 is adapted and configured to impart a rotational component of motion to the pressurized flushing fluid. This rotational component of motion aids in the axial movement of debris and its removal from the seal cavity of the pump.

[0026] Referring to FIGS. 6 through 11, in another embodiment of the present invention, a pump bushing 100 includes a cylindrical body 112 including two hemi-cylindrical portions 112 a and 112 b (see FIGS. 7 and 9) that are secured together by dowel pins (see FIG. 8). This configuration enables the pump bushing 100 to be installed in and/or removed from a pump, such as a centrifugal pump or a rotary pump, relatively easily. Preferably, the cylindrical body 112 has an axial bore 114 extending therethrough for accommodating an impeller shaft of the pump. As illustrated in FIG. 11, the pump bushing 100 includes a plurality of angled slots 116 that extend from an inlet port groove 126 to the axial bore 114, and terminate in an annular discharge groove 122 at the front end of the pump bushing 100.

[0027] The pump bushing 10, 100 of the present invention may have an overall length of approximately 1 to 4 inches (preferably 1-⅛ to 3-⅞ inches), an outside diameter (OD) of approximately 1 to 13 inches (preferably 2 to 12-{fraction (1/16)} inches), an axial bore diameter of approximately 1 to 11 inches (preferably 1-⅜ to 10-{fraction (9/16)} inches), an inlet port diameter of approximately 1 to 12 inches (preferably 1-{fraction (11/16)} to 11-{fraction (5/16)} inches), and an inlet port width of approximately ¼ to 2 inches (preferably ⅜ to 1-{fraction (15/16)} inches). The counter axial bore diameter is approximately equal to the impeller shaft diameter plus ⅜ inches. The counter axial bore depth is approximately ⅜ inches. The inlet port groove dimension is approximately ⅜ inches minimum with, for example, a radial depth of ⅛ inches. Preferably, the pump bushing 10, 100 is made of carbon graphite filled polytetrafluoroethylene (PTFE) or any other suitable material, including both metallic and non-metallic materials.

[0028] Although the pump bushing device and associated methods of the present invention have been illustrated and described with reference to preferred embodiments and examples thereof, other embodiments and examples may achieve the same results and/or perform similar functions. Accordingly, changes in and modifications to the pump bushing device and associated methods of the present invention will be apparent to those of ordinary skill in the art without departing from the spirit or scope of the present invention. The following claims are intended to cover all such equivalent embodiments and examples. 

What is claimed is:
 1. A pump bushing device that is adapted and configured to admit pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of the pump bushing device, the pump bushing device comprising: a cylindrical body defining an axial bore extending therethrough for accommodating a shaft of a pump; a plurality of circumferentially spaced-apart, axially-extending, angled slots formed in an inner peripheral wall of the axial bore; a plurality of apertures corresponding to the plurality of angled slots, the plurality of apertures extending radially inward at an angle from the outer periphery of the cylindrical body to the axial bore; and wherein the plurality of angled slots and the plurality of apertures receive pressurized flushing fluid.
 2. The pump bushing device of claim 1, wherein the cylindrical body comprises two hemi-cylindrical portions.
 3. The pump bushing device of claim 2, wherein the two hemi-cylindrical portions are secured together by a plurality of fasteners.
 4. The pump bushing device of claim 3, wherein the plurality of fasteners comprise a plurality of fasteners selected from the group consisting of threaded fasteners and dowel pins.
 5. The pump bushing device of claim 1, wherein a plurality of inlet ports are in communication with an inlet port groove.
 6. The pump bushing device of claim 1, further comprising an annular discharge groove formed in the cylindrical body at an end of the axial bore.
 7. The pump bushing device of claim 1, wherein the pump bushing device comprises a rotary pump bushing device.
 8. The pump bushing device of claim 1, wherein the pump bushing device comprises a material selected from the group consisting of polytetrafluoroethylene (PTFE), a metallic material, and a non-metallic material.
 9. The pump bushing device of claim 1, wherein the pump comprises a centrifugal pump.
 10. The pump bushing device of claim 1, wherein the shaft comprises an impeller shaft.
 11. A method for admitting pressurized flushing fluid into a seal cavity of a pump, flushing debris therefrom without removal of a pump bushing device, the method comprising: providing a cylindrical body defining an axial bore extending therethrough for accommodating a shaft of a pump; providing a plurality of circumferentially spaced-apart, axially-extending, angled slots formed in an inner peripheral wall of the axial bore; providing a plurality of apertures corresponding to the plurality of angled slots, the plurality of apertures extending radially inward at an angle from the outer periphery of the cylindrical body to the axial bore; and wherein the plurality of angled slots and the plurality of apertures receive pressurized flushing fluid.
 12. The method of claim 11, wherein the cylindrical body comprises two hemi-cylindrical portions.
 13. The method of claim 12, wherein the two hemi-cylindrical portions are secured together by a plurality of fasteners.
 14. The method of claim 13, wherein the plurality of fasteners comprise a plurality of fasteners selected from the group consisting of threaded fasteners and dowel pins.
 15. The method of claim 11, wherein a plurality of inlet ports are in communication with an inlet port groove.
 16. The method of claim 11, further comprising providing an annular discharge groove formed in the cylindrical body at an end of the axial bore.
 17. The method of claim 11, wherein the pump bushing device comprises a rotary pump bushing device.
 18. The method of claim 11, wherein the pump bushing device comprises a material selected from the group consisting of polytetrafluoroethylene (PTFE), a metallic material, and a non-metallic material.
 19. The method of claim 11, wherein the pump comprises a centrifugal pump.
 20. The method of claim 11, wherein the shaft comprises an impeller shaft. 